Abstract
A profile of tritium concentrations measured in the unsaturated zone in loessial sediments in a semiarid area is interpreted in terms of mobile and immobile water domains, according to a physical nonequilibrium transport model. The mobile domain is represented by percolating fresh water from both rain and irrigation, and the immobile one is represented by isolated fossil saline water pockets. The two domains are connected by partially-saturated narrow passages within dispersed clay minerals. The transport of the mobile water is described by convective-dispersive flow and mass exchange between the two water domains takes place simultaneously. The relevant equations with the given initial - boundary conditions are solved numerically, and the simulated profile is adjusted to fit the measured profile. By taking into account variations of the mass exchange coefficient in relation to matrix characteristics, we were able to obtain an adequate reconstruction of the measured profile. Temporal changes in matrix characteristics are attributed to dispersion kinetics of clays at the interface between fresh and saline waters.
| Original language | American English |
|---|---|
| Pages (from-to) | 235-240 |
| Number of pages | 6 |
| Journal | Developments in Water Science |
| Volume | 36 |
| Issue number | C |
| DOIs | |
| State | Published - 1 Jan 1988 |
| Externally published | Yes |